Answer:
a) t = 56.34 minutes
b) v = 5.32mph
c) t = 47.22 minutes
d) v = 6.35 mph
Explanation:
Given;
The speed of Ilya and Anya are
Run = 8.90mph
Walk = 3.80mph
distance = 5.00 miles
a) anya walk half the distance and run half the distance.
Speed = distance/time
time = distance/speed
t1 = 5×0.5/3.80 = 0.658hr
t2 = 5×0.5/8.90 = 0.281hr
t = t1 + t2 = 0.658+0.281 = 0.939hr × 60minutes/hr
t = 56.34 minutes
b) average speed = total distance/total time taken
v = 5.00miles/0.939hr = 5.32mph
c) Ilya walk half the time and run half the time.
t1 = t2 = t/2
Distance = speed × time
Substituting the values.
5 = 3.80(t/2) + 8.90(t/2)
5 = 12.70(t/2)
t = 10/12.70
t = 0.787 hr × 60 minutes/hr
t = 47.22 minutes
d) average speed = 5miles/0.787hr
v = 6.35 mph
